Optically, the Sigma looks very good, and the bokeh is excellent.
There is a reason I warned against making generalizations from one comparison only. Here is an example of less than excellent bokeh:
You must have used a lens extensively to know its weak and strong sides. The bokeh performance can really surprise you in many situations.
the sigma 35 CAN get busy...and not handle busy backgrounds as well ...as ...say the 85L II, but this shot below is ALSO how well it can do.... you have to be careful with any lens if you are shooting for bokeh..
here I see
smooth and nearly identifiable secondary figures...smooth transitions...all judgement of course